Running Head: TURBINE ENGINE DEVELOPEMNT
Michael Smith
HIST 130
Early Development of the Turbine Engine
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TURBINE ENGINE DEVELOPMENT
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Introduction:
During World War Two piston-driven aircraft was the primary form of aircraft in use.
However, during the war, there was development in a different type of engine. One that would
change aviation and make it what it is today. Aviation would not have exceled without the
invention of the turbine or jet engine. In this paper, we will look at the development of the
turbine engine. From the conceptual stage to production use in some of the first fighter aircraft
used at the end of the war. We will look at what came to be the inspiration for a turbine engine.
Furthermore, we will look at some of the technical issues first encountered during the
developmental stages of turbine engines, and another powerplant born from the turbine.
The Jet Engine:
According to Ernst Heinkel (1956), he was convinced that 500 mph was the peak of
propeller engine driven airplanes. With that being said, how do we reach faster speeds? The
turbine engine is the answer. There are two pioneers of the turbine engine, Sir Frank Whittle of
England and Dr. Hans Von Ohain of Germany. Ohain and Whittle are considered co-inventors of
the turbojet, pioneered the turbojet revolution (Meher-Homji, Prisell, 2000). While both did not
know of each other, they shared the same visions. Both envisioned speeds faster than 500 mph
and cruising altitudes of 30,000 feet, and both also developed their engines without help from
traditional aero-engine companies. It may surprise most that the principle of the turbine engine
emerged in the early development of aeronautics, but it never passed the stage of speculation
(Heinkel, 1956). So now the question of why these two pioneers put their finances and
reputations on the line for speculation and theory.
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These pioneers had a drive and a passion for expanding the turbine technology. They
viewed the turbojet as the new form of propulsion for aircraft. With faster speeds and higher
altitudes, the aircraft could fly farther. Frank Whittle performed the first run of his engine in
1937 and is claimed to be the engine that heralded the advent of the turbojet (Parker, Fedder,
2016). However, Ohain successfully ran the Hes. 1 engine in the same year as Whittle, but the
work was kept a secret even from the German Air Ministry. These early engines were plagued
with fuel atomization issues, component failures due to the composition of components and
heat, and the overall designs of compressor combustor and turbine sections.
The original designs were a centrifugal type turbine. Whittle (1954) explains that a
centrifugal is similar to but significantly more substantial than an aero-engine supercharger or a
fan unit in a vacuum cleaner. The original design had a compressor impeller and a turbine
wheel connected on a shaft. The revolutions per minute were 17,750 rpm which is blazing
speed in the time. Even though the first engines had issues, they exceeded their testing, and
engineers identified what the faults were. An engineer for Ohain, Max Hahn, had an idea to
move the combustor to the vast unused space in front of the centrifugal compressor, this would
reduce size and weight (Meher et al., 2000). Ohain implemented into the design immediately.
Both Frank Whittle and Dr. Hans Von Ohain received support from manufacturers.
Whittle started working with Rolls Royce, the manufacturer of the famous Merlin engine. Also,
Ohain was hired almost immediately on the spot by Ernst Heinkel. The backing by these
powerhouses opened up doors of financial support and untapped engineering talent to aid in
developing turbojet technology. With support from these companies, the centrifugal engine
was able to be produced into something as a viable powerplant for an aircraft. The
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development took off. Rolls Royce worked with companies such as Pratt and Whitney which
was based in the United States, and Pratt was authorized to build Rolls Royce engines in
America, for the U.S. government. However, the Turbojet was not the only engine tech to come
from this era of development.
While this paper is about the turbojet, we cannot help to mention another form of
propulsion that came from turbojets for this still need to mention the turboprop. While
America was wrapped up in developing and building jet engines, Rolls Royce started working on
a propeller-driven propulsion system. The turboprop, which is still used to this day, was first
developed by adding a gearbox to drive a propeller on the front of the turbojet. Rolls Royce
accomplished this by adding another turbine stage and a gearbox to the front of a production
turbojet (Parker et al., 2016). The gearbox is what drove a five-bladed prop. Most larger aircraft
now utilize jet engines; however, there are some smaller regional airlines and executive aircraft
still using turboprops as the propulsion choice.
As turbojets progressed in their development, we see a shift from centrifugal design to
what is known as the axial design. The axial design is what we see today in the modern jet
engine. By using a, straight through design, the engine can become more efficient. This is
accomplished by placing the compressor in front of the combustor and then proceeded by the
turbines. However, to increase this efficiency, engineers would need to look at new ideas. From
the axial engine, we see nowadays what is known as the turbofan. The turbofan is an axial flow
turbine engine with a bypass section around the core of the engine. On the front of the engine
mounted to the low-pressure spool is a substantial fan. The fan moved large amounts of air
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through the bypass, much like a propeller (Parker et al. 2016). The new turbofan became the
choice engine for all civil jet power to this day.
While the jet engine was a transformative innovation, the development was not easy. In
both the U.S. and Britain, there were issues with heat dissipation, making alloys to withstand
the heat and rotational speeds, and high fuel consumption (Scranton,2011). However, even
with these issues a comparison in 1944 between propeller and jet propulsion the military
desired jet propulsion to be in all fighter aircraft. The propeller engine had limitations on range
and speed (Scranton,2011). Turbine engines were the future of aviation, and the Airforce knew
this. The military’s interest in the jet engine is what fueled the development of manufacturers.
A Major General for the U.S. Airforce found $14 million in un-used allocations in which
he tried to transfer into development at GE. Unfortunately, his initiative was stopped by policy
changes, and this stopped the jet engine program in 1946 (Scranton,2011). The injunction did
not stop the military. They felt threatened by not becoming the leader in jet aircraft and came
up with a plan. The Airforce came to an agreement with GE to produce a new engine and use
$4 million of GE’s reserves provided the Airforce delivered a substantial order in advance of
prototyping or testing. Both Britain and the U.S. manufacturers benefitted from military aid,
and the jet engine was able to transform aviation as we know it today.
Conclusion:
Without both Sir Frank Whittle and Dr. Hans Von Ohain, we do not know when the
turbine engine would have been developed. As Heinkel (1956) states, the turbine engine did
emerge in the early developmental stages of aerodynamics. So, one would assume eventually
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we would see the engine come to fruition. By utilizing the design of supercharger from a piston
engine, Whittle and Ohain were able to add combustion chambers and make it running engine.
Through the trials and tribulations, both were able to develop a running engine and influence
the leaders of their time. As knowledge grew and traversed companies and countries, we see
engine manufacturers working to develop their own designed engines. This leads to military
might wanting their country to be the leader of jet propulsion.
We then see military backing to aid in developing substantial engines of reliability and
range. The advancements lead the manufacturers into the high bypass engine. The bypass
engine is what we see on all civilian jets today. These engines provide efficiency, range, and
noise reduction, compared to their military counterparts. Without the development of the
turbine engine, it is hard to imagine were aviation would be today. The turbine and all the
masterminds behind its inception are what have propelled our global aviation to what it is
today. Without the first steps from Whittle and Ohain, we may not have turbine engines that
perform the way they do today.
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References:
Giffard, H. (2016). Making jet engines in world war ii: Britain, germany, and the united states.
Retrieved from https://ebookcentral.proquest.com
Heinkel, E. (1956). Stormy Life: Memoirs of a pioneer of the air age (First ed.). New York:
Dutton.
Meher-Homji, C. B., & Prisell, E. (2000). Pioneering turbojet developments of Dr. Hans Von
Ohain—From the HeS 1 to the HeS 011. Journal of Engineering for Gas Turbines and
Power, 122(2), 191. doi:10.1115/1.483194
Parker, R., & Fedder, G. (2016). Aircraft engines: A proud heritage and an exciting future. The
Aeronautical Journal, 120(1223), 131-169. doi:10.1017/aer.2015.6
Scranton, P. (2011) Mastering failure: Technological and organisational challenges in British and
American military jet propulsion, 1943–57, Business History, 53:4, 479504, DOI: 10.1080/00076791.2011.578130
Whittle, Frank, Sir, 1907. (1954). Jet, the story of a pioneer. United States: